Wiring for electric-call-bell circuits.



G. A. PIERCE.

WIRING FOR ELECTRIC CALL BELL CIRCUITS.

APPLICATION rum) MAR. 24, 1910.

1,067,194. Patented July 8, 1913.

COLUMBIA vLANuuRAPn co, WASHINGTON. n. c.

GEORGE A. PIERCE, OF PHILADELPHIA, PENNSYLVANIA.

WIRING FOR ELECTRIC-CALL-BELL CIRCUITS.

LWWJEM.

Specification of Letters Patent.

Application filed March 24, 1910.

Patented July 8, 1913.

Serial No. 551,407.

To all whom it may concern Be it known that I, Gnonon A. Pinncn, acitizen of the United States, residing at Philadelphia, in the county ofPhiladelphia and State of Pennsylvania, have invented certain new anduseful. improvements in \Viring for Electrio-Call-Pel Circuits, of whichthe :lollowiug is a specification.

My invention relates to that class of wiring wherein a plurality ofstations are providedwith electric calling apparatus that inter-connectseach station with the other, and my objects are-first; to provide asystem of wiring whereby the sending station may know that the operativecircuit is completed through the receiving station, and second; toprovide a system of wiring that will reduce to a minimum the number ofinter-connecting wires leading from each station.

WVith these objects in view, my invention consists in a certain novelfeature in the arrangement of wiring as will hereinafter be more fullydescribed and pointed out in the claim, reference being had to theaccompanying drawing, forming part of this invention and in which thefigure is a wiring diagram which shows a plurality of stations wired inaccordance with my improved method of wiring.

An application of the above-described wiring as applied to a pluralityof stations is shown in the figure, wherein three stations are shown,viz: A, B and C, and between which signals are desired to be exchanged.

In said figure A designates a local station at which are located theannunciator drops a and a. 37 and 38 designate the contact points of atwo-point switch and 39 and 40 designate contact points of a similarswitch. 41 designates an alarm at said station to give an audible signalthat the station is being called.

B designates a similar station to that of A and is provided with theannunciator drops 7) and Z). 27 and 28 designate the two points of atwo-point switch and 29 and 30 designate similar points of a similarswitch. 35 designates an alarm in the locality of said annunciator dropsto give an audible alarm when said station 13 is being called.

C designates a similar station to that of A and B and is provided withannunciator drops 0 and c. 31 and 32 designate the two points of atwo-point switch and 33 and 34; designate similar points of a sii'nilarswitch. 36* designates an. alarm located near the said station C to givean audible alarm when said station is being called.

22 designates a source of clectro-motivc force that supplies electricenergy to said system.

1, 52, 3 and 4t designate leads intcr-connect- I ing station B to saidA. and G.

5, 5, 7 and S de nate leads inter-connect ing station C to stations Aand B and l), 10, 11 and 12 designate leads inter-connecting station Ato stations 13 and C, all of which will be readily understood by thoseskilled in the art to which. this invention relates.

Having thus described the various elements and wirii'ig connectionsthroughout the several views, its mode of operation will besubstantially as follows: It is desirous of station A to call station13. The operator at station A will move the blade of the twopoint switchon the contact point 37 and a closed circuit will be established asfollows: from positive side of battery, lead 10, lead 42, contact 37,ani'iunciator drop a, lead 9, lead. 1, annunciator drop o, contact 28,lead 13, bell 35, lead 4: to negative side of battery. It is desirous ofstation A to call station. 0: The operator at station A will move theblade of the two-point switch on the contact and a closed circuit will.be established as follows: from positive side of battery, lead 10, lead42, contact 39, annunciator drop a, lead 12, lead 5, annunciator drop 0,contact 33, lead 4%, bell 36, lead (3 to negative side of battery. litwill be understood that the said switch will be returned to the normal.or off position when not in use.

From the foregoing description of the estal'ilished circuits it will. beseen that when the station A calls station B or (3 that the respectiveannunciator drop a or a will. be responsive to the operation of thetwo-point switch as well as the annunciator drop Z) or c, which arelocated at the station being called, thus accomplishing the heretoforefirst mentioned object of my said invention. It will be understood bythose skilled in the art to which. this invention relates that theamount of wiring necessary for the ordinary way of wiring will be onesection wire for each annunciator drop, one section wire for eachcircuit closing switch, and a positive and negative supply wire, or atotal of N+2 wires (N equals number of section wires and 2 equals thetwo supply wires). From my improved method of wiring it will be seenthat the number of wires required will be and for the circuits as shownrequires four wires from each station, whereas the ordinary wiring wouldrequire six. The difference becomes more prominent when a larger numberof section wires are used, as for instance twenty section wires plus twobattery wires would be reduced to ten section wires and two batterywires, thereby effecting a saving of wire and accomplishing theheretofore mentioned second object of my said invention.

I do not Wish to limit myself to the use of the exact apparatus asshown, as it is evident that numerous appliances may re place that shownon the drawing, but

\Vhat I claim as new and desire to secure by Letters Patent, is,

An electrical system of signaling between stations, the same comprisinga single source of energy, a plurality of signaling stations each ofwhich stations includes the same number of annunciators as there areremaining stations to be called, a single electromagnetic calling alarm,and the same number of plural point switches as there are remainingstations to be called, and operating circuits, said circuits including awire connection from one side of each alarm to one pole of the source ofenergy, wire connections from the other side of each alarm to contactsof the switches at the same station, a wire connection which connectsone terminal of one annunciator at each station with one terminal of oneannunciator at another station, a wire connection which connects oneterminal of each annunciator at each station to the blade of one of theswitches at the same station, and a wire connection from the remain ingcontacts of the switches at each station to the other pole of the sourceof energy.

GEORGE A. PIERCE. \Vitnesses DAVID R. KNAPP, JAS. T. SMYTH.

Copies of this patent may be obtained for five cents. each, byaddressing the Commissioner of Patents, Washington, D. G.

